Cherry

Humidity-driven, and worst on injured, split or bird-pecked cherries, which give the fungus an easy way in - rain in the last days before picking is the classic trigger.

Browned, collapsed blossoms in spring, sometimes with a small gummy canker on the twig behind them; firm brown spots on ripening fruit that erupt in tan fuzzy spores; and shriveled mummies clinging to the tree.

Fungicide at bloom for blossom blight, and again in the last two to three weeks before harvest if the weather stays warm and wet. Use only a product whose label lists your crop by name, and follow that label's pre-harvest interval - some stone-fruit fungicides (chlorothalonil, ziram) may not legally be sprayed that close to picking. Strip and destroy infected fruit the day you see it. Sanitation - clearing mummies and infected wood - is at least half the control.

Remove every mummy and rotted fruit - they are the spore source that starts next season - prune for airflow, thin so fruit don't touch, protect fruit from insect, bird and cracking injury (those wounds are the way in), and avoid wetting the foliage. Dry climates see far less of it.

The major fruit-rot disease of stone fruit: a fungus (Monilinia) that blights blossoms, cankers twigs, and rots ripening and stored fruit into fuzzy tan 'mummies' - it can destroy a ripe plum crop in days of warm, humid weather.

Because cherries ripen in a tight window and are a favorite bird food, a couple of unprotected days can cost the whole crop - which is why many growers keep cherries on dwarf rootstock, so that netting the whole tree is actually possible. Squirrels join in.

Fruit disappearing from the outermost, most exposed parts of the plant first, and from the top of a tree where you cannot reach anyway. Single neat pecks and gouges in ripening fruit, with several fruits sampled rather than one eaten through - the classic sign that it was birds rather than an animal. Heads of grain or seed going visibly lighter and emptier as they ripen, with hulls and chaff scattered underneath. Freshly sown seed vanishing off the surface of a bed before it germinates. Bird traffic in and out of the plant picking up as the crop colors, and birds waiting on nearby wires and branches. Wasps arriving at the pecked and split fruit shortly afterward.

There is no treatment once a crop is being taken - only protection and timing, so the answer is to get netting on and to pick what is ready. Reflective tape, flash ribbon, spinners, and decoy predators do work, but only for a few days at a time: birds habituate fast, so move and rotate them and never rely on them as the main defense for a crop you care about. Cut and gather grain or seed heads a little early, at firm dough, and finish drying them under cover instead of leaving them standing for the flocks. Plant a little extra, or a decoy crop the birds prefer, and accept sharing anything that crops heavily. On a wild or foraged patch, fruit going to birds and small mammals is the point of the plant rather than a problem to solve.

Net, and net early. Bird netting draped over a frame or hoops so it stands off the fruit, with the edges closed at ground level, is the only thing that reliably works at harvest scale - and it has to go on before the crop starts to color, because once birds have found the food they are far harder to displace. Keep fruit trees small enough that netting them is actually feasible; that decision gets made years earlier, at planting. Bags of mesh, organza, or paper slipped over individual heads, clusters, or prize fruit protect a small crop without netting the whole plant. Then shorten the exposure: pick promptly and completely rather than leaving ripe fruit hanging as a lure, clear split and dropped fruit that draws birds and wasps alike, and where a crop can finish off the plant, harvest a little early and ripen or dry it under cover. Rake in or cover broadcast seed so it is not lying in plain view.

Birds find ripening fruit and seed before you do. Robins, waxwings, starlings, catbirds, jays, sparrows, finches, blackbirds, and doves all work a garden, and the pressure arrives in a narrow window - the last days before harvest, when sugar rises, color changes, and the crop softens or the grain hardens. A flock can strip a small planting in a day or two, and birds that only peck rather than take whole fruit still leave wounds that rot or draw wasps. Squirrels, chipmunks, and other wildlife usually turn up on the same crop at the same time. This is competition rather than disease: the birds are not harming the plant, and a big tree or a heavy-cropping bush often has enough for everyone - but on a small planting it can be the difference between a harvest and none.

Trap-based timing is essential - the window to act is between adult emergence and egg-laying in coloring fruit.

Small white maggots inside cut fruit, soft brown depressions on the surface, and adult flies (with banded wings) caught on yellow sticky traps as fruit colors.

Targeted insecticide (e.g., spinosad) timed to adult emergence and egg-laying, guided by traps; repeat as the label directs through the ripening period.

Hang yellow sticky traps to detect adult emergence and time controls; harvest promptly and completely; clean up dropped and infested fruit to break the cycle.

A small fly whose larvae (maggots) develop inside ripening cherries - the classic 'worm in the cherry.' Adults lay eggs in coloring fruit; the maggots feed at the pit, leaving soft, brown, infested cherries. A key reason commercial cherries are sprayed.

Severity is High on sour/pie cherries (Montmorency, North Star, Meteor) in humid regions and Medium on sweet cherries. Rare in the arid West.

Small purple-to-brown spots on the upper leaf surfaces, yellowing leaves, and heavy leaf drop starting midsummer - a sour cherry that is half bare by August has it.

Protective fungicide from petal fall through the post-harvest period in wet regions - keeping the leaves on the tree after harvest matters as much as protecting the crop. Sanitation of fallen leaves each autumn breaks the cycle.

Rake and destroy fallen leaves, which is where the fungus overwinters; prune for airflow so leaves dry fast; avoid overhead watering.

A fungus (Blumeriella jaapii) and the dominant disease of sour/pie cherries across the Great Lakes, Midwest, and Northeast. Small purple spots on the leaves turn brown, the leaves yellow, and the tree sheds them from midsummer on. Heavy defoliation strips the carbohydrate reserves the tree needs to ripen fruit and harden off, leading to poor ripening and winter kill of buds and wood.

A game-changer pest since its spread - it attacks intact ripening fruit, so the old 'only overripe fruit' assumption no longer applies to cherries. Harvest early and often, and clear every dropped and overripe fruit from under the tree.

Soft, sunken, weeping fruit that collapses under light pressure, and tiny egg-laying scars on otherwise perfect ripening berries. To confirm, crush or float suspect fruit in salt water (1-2 teaspoons per cup) and look for small white maggots floating out. In an apple-cider-vinegar or yeast-sugar trap, the males carry a distinct dark spot at each wingtip.

There is no rescue for infested fruit. Control is relentless sanitation plus trap-based monitoring to time any spray: bag or freeze culls rather than leaving them, never drop them on the ground, and use vinegar or yeast-sugar traps to tell you when the flies have arrived. Well-timed targeted sprays such as spinosad are used where pressure is high - use only a product labeled for the crop you are treating, follow the label exactly, and observe its pre-harvest interval.

Pick short and often - every two or three days through the ripening window - and remove ALL overripe and dropped fruit, because culls left on the plant or the ground breed the next generation. Cool the harvest to about 35°F promptly, which stops larvae developing in fruit you have already picked. Fine mesh under 1 mm excludes the fly where pressure is high.

An invasive vinegar fly (Drosophila suzukii). Unlike ordinary fruit flies, which need damaged or overripe fruit, the female has a saw-edged ovipositor that cuts into sound, intact, ripening fruit to lay her eggs. The larvae feed inside, so the fruit softens, sinks, weeps and collapses just as you were about to pick it. It has become the dominant pest of soft fruit across the country, and the old rule that fruit flies only bother spoiled fruit no longer applies.